1. Technical Field
The following description relates to a gate driving circuit and display device which includes a plurality of shift registers.
2. Discussion of the Related Art
There has been an increasing demand for a display device for displaying an image together with the growth of an information-oriented society. Recently, various flat panel displays which reduce weight and volume corresponding to an advantage of a cathode ray tube are developed. For example, the various flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting diodes (OLEDs) have been widely used in recent years
The flat panel display displays an image by using a gate driving circuit which sequentially supplies gate signal to gate lines of a display panel, and a data driving circuit which supplies data voltages to data lines of the display panel. The gate driving circuit is implemented by a TAB (tape automated bonding) method which attaches printed circuit board mounted a gate drive integrated circuit (IC) to the display panel, or a GIP (gate drive IC in panel) method which forms the gate drive IC on the display panel. The flat panel display can be slim when the gate driving circuit is implemented by the GIP method. Thus, a manufacturing firm may design an appearance of the flat panel display by considering the beauty. Also, a display panel maker may lay out the gate signal and a cost of fabricating the display panel may be reduced when the gate driving circuit is implemented by the GIP method.
Meanwhile, a complexity of the gate signals may be increased for improving a picture quality. For example, the gate driving circuit includes a plurality of shift registers which generate a plurality of gate signals. The gate driving circuit needs a multiplexer for selecting any one gate signal among the plurality of gate signals generated from the plurality of shift registers. The gate driving circuit sequentially supplies the selected gate signal by the multiplexer to the gate lines.
However, a size of the multiplexer should be greater than a buffer size of the shift register in order that the multiplexer pass on the gate signal to the gate line without a loss of the gate signal. A layout area of the gate driving circuit gets bigger as the size of the multiplexer is greater. Also, a bezel area of the display device becomes wider. The bezel area is a side of the display device. The image is not displayed on the bezel area corresponding to a non-display area. The gate driving circuit is formed on the bezel area when the gate driving circuit is implemented by the GIP method.
Also, a switching element of the multiplexer may be deteriorated if the multiplexer is driven for a long time. The deterioration of the switching element causes a loss of output of the multiplexer.